Expansive underreamer



Jail 5, 1932. w. N. PACKER EXPANSIVE UNDERREAMER Filed Oct. 8, 1928 5 Sheets-Sheet Jan. 5, 1932. w. N. PACKER EXPANSIVE UNDERREAMER Filed oct. s, 192s 3 Sheets-Sheet 2 Jan. 5, 1932. w. N. PACKER 1,839,771

EXPANS I VE UN DERREAMER Filed Oct. 8, 1928 3 Sheets-Sheet 3 Mor/Qq.

' and strong.

Patented dan. 5, 1932 STATE rarsnr ori-nes winnaar) n. rnoxnn, or SAN PEDRO, CALIFORNIA, nssrenon To Jenn GRANT, or'Los ANGELES, oALIFon-ivrn j v ExrANsIvn UNDERREAMER Application led October 8, 1928.- Serial No. 310,961. i

This invention has reference to the art of rotary under-reaming in wells and the art of expansive reaming tools; and the general object of the invention is the provision of a f simple, reliable, and rugged form ofunderrea-mer or expansive reamer.

The diiiiculties encountered in practical operation of rotary underrea-mers are many. The tool must not only be capable of efficient `f reaming action, but must be dependable to the point of iniallibility and must be rugged r[he space in which the tool must work isrseverely limited, especially in the smaller sizes of drill holes;and a large majority of rotary underreamers which have lbeen proposed or designed in the past have failed for various reasons but perhaps chiefly because of complications of parts and structures, which complications and multiplicity of parts inevitably leads `to smallness land Weakness of parts. Y

It is an object of this invention `to provide a design of underreamer of a type expanded by relative rotation and which is very simple and is composed of relatively large strong parts, with cutting elements strongly supported; and these objects are, speaking generally, accomplished in my invention by the provision and use of cutters or cutter carriers which, extending in a general longitudinal or vertical direction, are tiltingly mounted at one end, as their lower ends, and so mounted at their upper ends that tilting movement of the cutter or cutter carriercauses the upper endl to move outwardly to an'` expanded and operative position. ln the designs `hereinafter described the ultimate cutting element is shown in the form of a cutting roller surrounding a cutter-carrying pin or mandrel; and although this at present is the `preferred specific design and embodiment of the invention, it .will be recognized that the specific form of the ultimate cutting element is not necessarily a restriction upon the invention in its broader aspects.

Other objects and correspondingl accomplishments of the invention will appear from the following detailed specification describing the preferred and illustrative forms and embodiments of the invention, and for thisk purpose reference is had to the accompanying drawings in which:

`ig. 1 is a side elevation of one form of my improved reamer showing the cutting .elements in their collapsed or inoperative position. y

Fig. 2 is a fragmentary side elevation and vertical section showing the cutters in their expanded positions.

Fig. 8 is a cross section on line 3-3 of Fig. 1.

Fig. 4 is a cross section on line et+-4.0i Fig. 1.

Fig. 5 is a cross section on line 5 5 of Fig. 2.' i

Fig. 6 is a side elevation of another form in collapsed position;

Fi g-7 is a fragmentary side elevation with parts in section showing the same reamer in its expanded position. f f

Fig. 8 is across section on line 8--8 of Fig. 7.

*ig 9 is a side elevation of another form of the reamer.

Fig. 10 is a fragmentary side elevation;-

showing the reamer of Fig. 9 in expanded position.

Fig. 11 is a cross section on line 11-11 of Fig. 10. Figs. 12 and 13 are cross sections on lines 12`12 and 13-13, respectively of Fig. 9.

Referring first to Figures 1 t0 8, the numeral 10 designates a suitable body provided at its upperL end with the usual tool joint pin 11 for connection with a, rotary drilling string, and at its lower end with the usual'tool joint box 1Q'or connection with adrilling bit 13. The body, in the design herein shown, coman intermediate reduced part 16 which is here shown as triangular in cross section; the.

reamer being here illustrated as having three cutting elements, although any suitable number of cutting elements may, of course, be-

used. The lower head 15 is provided with a plurality of bosses 20 which form the sup,

ports for the lower end of the cutter mandrel pins 21. These mandrel pins are so supported at their lower ends that they may swing "cutters strik-ing Vthe casing or shoe=causes-the cutters -fto be moved baclrto their contracted positions tand'the'toolfm'ay then be withdrawn through fthe# casing.

or tilt on their lower ends; and for that purpose the simple design shown in the drawings involves a vertically extending pin-receiving aperture 22 which extends down into the boss 20, the lower end of pin 21 extending down into this aperture and being held loosely in place by a transverse dowel pin '23 which is driven tightly through the boss 20. Apertures 22 are elongated, see Fig. 3, to allow the "tilting motion of mandrel pins 21. The up,-

per end surface of boss 2O is cylindric, to :pros

vide the cylindric bearing surface 24 preferably concentric with the rounded lower end of pin 21, as shown in the drawings. The ax-isof this cylindric bearing surface is, in the speciiic desi-gn herein shown, radial to fthe center of the whole tool, that axis vbeing Arepresentedby the broken line indicated at A in lFigures 3 and 8. A0n this cylindric Abearing surface as a 'bearing `washer 25 which has 'a correspondingly cylindric under surface; and vthe lower end of the roller'cutter 26 rests and bears -upon the fiat upper surfaceof this bearing washer 25. The construction is such as 'tolgiv'e agood tilting bearing for the lower end of the cutter element to tilt or swing about'thehorizontal Aaxis AZ, also algood end 6to the tilted positions shown in Figure 9,

'the upper ends vare moved-outward from the center of the tool and the cutters are thus'expanded. In thusmovingto their tilted positions, the upper ends of the cutters not'only move outwardly, but also lmove circumferentially lofthe tool ,theyrmay be saidto move in a tangential direction. And thus vmoving -tangentially, right-handed `rotation of the body causesfthe upper-endsof the-cutters to xmove not centrifugally and,=coming into con- 'tafct withthe'wallof thehole, the drag onthe cutters then drags them out to-'their'fully exip'anded'positions. YWhen it is desired to contractthe critters they may be contracted-merexlly bypullingthem'up against the lowerend 'ofthe casing. vthetool is rotating or whenthe -tool'is'rotau tively still. 'It rvis lnot necessary Jto revolve This may-be done either while backwardly (left-handedly) to collapse the 'l he upper Ybeveled surfaces 26a 'At theupp'er ends of thefroller cutters upthrust bearing washers 26?) are provided. The rollers 26 thrust up against the washers; and the washers thrust up against the up-thrust bearing faces 140 which liearound the slots 27 and are preferably curved and concentric, or substantially so, with the centers of tilting at the low-er ends of the cutter elements. The washers, however, do not rotate with the cutters 2 6; they have lugs 260 which project into the slots 27 and thus prevent the washers from rotating. rihe rotary bearing faces for rip-thrust are thus at the lower faces of washers 265; just as the down-thrust rotarj' bearing faces for the rollers 26 are at the upper face of washers 25. Thus, grease or other lubricant :packed into the rollerk cavities 26d will work out between the end thrust rotary bearing faces, keeping them lubricated and .preventingentry of mud etc. to all the bearing surfaces of the rollers.

rlhe description so far given -applies to both forms shown in yFigures 1 to 8, inclusive, both forms being fundamentally similar. ln the form shown in AFigures 6 and 7, the body isdesigned as one integral piece andthe cutter Epins 21 are removed by removing the do'wel lpins 23 and Vthen Lrnoving ythe vcutter pins upwardly through the openings 30 which extend throughthe upper head 14. In the form of Figuresl and 2 the mandrellpins `are removed upwardly through recesses-30a'l which Aare positioned over the mandrel Apins and communicate with the annular recess of `juncture S dividing the upper head HasA shown in Figs. 1 and 2. The recess 301) is s'how'n yas formed in the upper vpart 14d; and

the slots 27 are formed in the lower part 14e,

ofthe -upper head 14.

In the formfof Figures 1 to 5 special mem'- Ibers arefprovided for facilitating contraction of vthe-cutters by' pulling the tool up into the lower endof the casing. The upper ends of the mandrel pins 21 play in the tangential slots27 vasbe'fore described, and themotion 4for contractioniand expansion is'thesame as before described. ,But in the upper-head le there are three pivoted lingers 35, one for each cutter, and'each -ofthesefingers ispro- Avided with a lug 36 having at itsfouteredge -an incline-d'fa'ce which,\upon being pulled up against the lower end of the casing, causes theliing'ersfto be `pressed inwardly. Theex-V panded position of the-partsis shownv in Fig-V -nre-5 andfit will be apparent howthe inward Vswinging -movementof the lingers 35 causes movement ofthe upper ends of-the cutter elements to ltheir collapsed positions, the

parts moving to the positions shown in Fig- CTI vure 4. In the collapsed'positions 'the upper specifically necessary to the operation of the device; it being only necessary that the pivoted fingers contact withthe upper ends of the mandrel` pins soy that inward swinging movement of the fingers will cause collapsing movement of the mandrel pin. But the pin receiving notches in the outer swinging ends of the fingers provides a simple and effective means for limiting the outward swinging movements of the fingers, without the necessity of providing special stops for the fingers on the body. Y

The body, in the form which has been described is provided with the usual longitudinal watercourse l0 extending through it to feed circulating iiuid to the water-course 18a of the drill bit below. Aliso, if desired, holes 40a may be drilled in the upper part of the body (see particularly Figures 2 and 8) for directing a certain amount of water or circulating fluid outwardly against the cutters 26. rl`he bosses 20 may be provided with slots or openings 20a which lead from' the pin-receiving apertures 22; so as to facilitate lifting the mandrel pins for removal and so as toV allow circulation of fluid through the apertures 22 and around the lower ends of mani drel pin 2l, to maire those parts self-cleaning. And, if desired, circulation holes may also be provided, as shown at 22a; in Figure 3, leading from the passage l0 to each of the boss apertures 22, to provide positive circulation through theaperture 22 and around theV lower ends of pins 21.

ln Figures 9 to 13 a somewhat modifiedV structure is illustrated, involving the same principles of design and operation, as hereinbeiore described, but showing a different detail of structure and assembly. Here the body l0 is also made preferably in one integral piece with an upper enlarged part or head le@ in which are provided the tangential slots 27a. The reamer here is shown as having four cutter elements and the central portion 16a of the body is' therefore shown as square in cross section. The lower ends of the cutter mandrel pins 21a are mounted on hubs'21b which swing on the radial pivot pins 50. These hubs 215, and the lower ends of the mandrel pins, are held inwardly by a confining ring lwhich en-4 circles the hubs 2lb, fits over the outer ends of the pivot pins 50, and thus strengthens the whole structure and prevents outward movementofthe hubs 2lb. This encircling ring 51 may be made in any suitable form; and is shown here as being formed in'halves and bolted together as at 52. The up-thrust of.,

the cuttersxis taken in the same manner as before described-'through bearing washers 26o which bear avainst the thrust surfaces i4 b The mandrel pins 21a, and the roller cutters 26 thereonswing on the horizontal radial axes of pivot pins 50; but the fit of the hubs 2lb on the pivot pins maybe somewhat loose so as to allow the upper ends of the mandrel pins a little loose play. Thus, with suchV loose play, it is not necessary that the slots 27a in the upper head il@ be made exactly straight or exactly at right angles to the axes of pins 50, and the slot 27a may also be provided with inwardly extending notches 276 at their outer ends, intowhichnotches the upper ends of the mandrel pins 21a are pressedbacl by. the forces which tend `t0 press the cutter elem-ents inwardly when the tool is in operation. The notches thus opei-4 ate to prevent the mandrel pins and the cutting` elements fronimoving back to their collapsed positions as long as the cutting ele.- ments are being pressed inwardly by pressure against the wall of the hole. Y And the somewhat inward curved formation of the outer ends of the slots 27a may also have the same general effect, as will readily be recogl2. Generally speaking, either the curva vture of the slots or the provision of notches at their outer ends, provides a slot which eX- tends generally tangentially or generally in a direction substantially at right angles to the swinging axis of the cutter, but at its outer end extends somewhat inwardly of that tangential direction (inwardly toward the y center of the tool). slot 27a areopen so that when the mandrel pins 21a are in substantially the expanded wpositionsof Figure ll they may be removed directly outwardly from the slots 27a after the encircling band 5l is taken 0E and the lower hubs 2lb are slipped outwardly on the pivot pin 50,

The cutting teeth on rollers 2G are of spiral formation; they are here shown as a coarse spiralV-sliaped thread'. Depending on the pitch ofthe thread, whether right or lefthanded, the action of the cutter `on the formation tends to force the cutter endwise in one direction or the other. For instance, in the drawings, the threads being shown righthanded and the tool being normally rotated right handed viewed from above, andV contact with the formation causing the roller cutters to rotate left-handed viewed from above; the cutters tend to screw themselves up in the formation and the shearing action of the spiral on the formation cuts the earth downwardly.

The outer ends of the This upward Ypressure on the cutters throws them up against their upper end thrust bearings at the surfaces 140, and, by creating friction at ,that point, tends to hold the cutters in their expanded Ypositions .against any accidental collapsing movement. Gn the other hand, if `the tool be reversely rotated to collapse, the cutters then roll right-handedly and tend to screw ,themselves down onto the lower rthrust bearings ,at 2lb,

' relieving the friction at the top and making Amounted on the body and extending vertically the lower end of the cutter element being mounted on the body for tilting about its lower end, in a plane tangential of the body,

the cutter element ,being substantially immovable longitudinally of the body, and uptlnust bearing means for the cutter element including a downwardly facing thrust surface on the body.

Y 2. In an expansive roaming tool, a vert-ically elongate .body adapted .to be rotated about a central vertical axis, a cutter Velement Vmounted on the body and extending vertically, the lower end of the cutterelement b eing mounted on the body for tiltingabout vits lower end, in a plane tangential of the body, the cutter element being substantially immovable longitudinally of the body, and

upthrust ybearing means for the cutter .ele-K .nient including a downwardly facing Athrust surface on the body, substantially concentricl about the lower end of the cutter element.

3. In an expansive reaming tool, a vertically elongate body rotatable about a central vertical axis, a vertically extending mandrel pin, a rotatable roller cutter surroundk the mandrel pin, the mandrel @pin projecting above and below the upper and lower ends respectively of the rollercutter, means mounting the ,lower end of themandrel `pin von the body for swinging movement of the mandrel pin about its Vlower end asa center, fthe upper partof the body having slot in a plane substantially tangential .tothe body, the upper end of the mandrel pin entering and being guided by said slot, and upthrust bearing means for the roller cutter including a downwardly facing surface, onthe upper part of the bodyaround the guide slot and above the upper end ofthe cutter.

4. In an expansive roaming tool, a body,

inserm a cutter carrying member vmounted at one end on the body to swing about an axis transverse of the body, the Ybody having a cylindrical bearing surface near and concentric with vsaid transverse axis, a bearing washer on the cutter carrier and having a cylindric bearing surface contacting with the 'bearing surface ,of the body, and va cutter ,on the carrier resting-uponthe washer. Y

15,111 .expansive .reamng tool, a verti- -cally elongate 'body rotatable about la central vertical axis, A a vertically extending Vmandrel pin, nieans'loosely connecting the Vlower end vof the mandrel pin with the body to allow tilting ofthe mandrel pin about'the lower end, a :cylindric bearingfsurface on the body substantially concentric with the lower end of the Amandrel pin, a washer surrounding the mandrel pin andhaving l a lower cylindric `bearing surfaCe Iadapted to Vbear upon the cylindric vbearing surface ofthe body, yand Aa rotatable roller v cutter carrier upon the mandrel pin and resting upon the upper surface of the washer.

6, ln `an expansive roaming tool, a vertically elongate body yrotatable about a central yertical axis a C utteixeleinent extending verticallyalon'gthe exterior of the body and mounted on the body at its low-er end for tilting movement, means yin the body for guiding the upper end of the cutter element jin such tilting movement, and a -pivoted linger mounted `:in the upper part of the body and engaging the upper end'of `the cutter element and having an outer diagonal face adapted to'be engaged bythe lower end of-a wellcasv@ing whereby to move ,the linger and the upper end ofthe cutter element inwardly.

' 7. AIn an expansivereaming tool, a vertical- :ly elongatebody rotatable'abotlf a central verticalaxis, acutter element extending vertically along the exterior of the body and mounted on the body at its lower end for tilting movement, means inthe body for guiding the upper, `end of the cutterelement in such tilting movement, and a horizontally swinging pivoted -nger mounted in the upper. aart .of the body and @teasing the .up- Kper end ofthe cutter element and hav-ing an outer diagonal faceadapted to be engaged by -the lower end of a well casing whereby to movethe finger and the upperen'd of the cut` ter element inwardly.

8, yIn ,an rexpansive reaming tool, a vertically Velongate body rotatable about a central I vertical axisa lcutter carrying mandrel pin extending vertically yof the bodyand having lits lower end mounted in thebo'dy for tilting motion, a cutter mounted on'the lmandrel pin, means in the upper part of the body guiding` the upper enfd ofthe mandrel pin in vmovement 'in a vvplane nonra'dial of the body, and a member'movably mounted jou the body, having a casing contacting Ipart movable substantially radially of the body,

and engaging the mandrel pin to move it non-radially.

9. In an expansive reaming tool, a vertically elongate body rotatable about a central vertical axis, a cutter element extending vertically of the body and having its lovver end mounted in the body for tilting motion, means in the upper part of the body guiding the upper end of the cutter element, in movement in a plane non-radial of the body, and a member movably mounted on the body, having a casing contacting part, movable substantially radially of the body, and engaging the cutter element to move it nonradially.

10. In an expansive reaming tool, a vertically elongate body rotatable about a central vertical axis, a cutter element extending vertically of the body and mounted thereon to be movable non-radially with respect to the body, and a member movably mounted on the body, having a casing contacting part movable substantially radially of the body, and engaging the cutter element to move it non-radially.

11. In an expansive reaming tool a vertically elongate body rotatable about a central vertical axis, a vertically extending cutter carrying axis pin mounted in the body, a

roller cutter mounted directly on said axis pin to revolve thereon as a bearing, the body having a slot extending transversely of the body axis and substantially tangentially of the body, and an end of the axis pin entering into and guided directly by said body slot.

12. In a rotary expansive reaming tool, a

c vertically elongate body adapted to be rotated about a central vertical axis, a cutter carrying mandrel pin extending vertically of the body and mounted in the body for tilting motion, a roller cutter on said mandrel pin having end thrust support on the body, and said roller cutter having a spiral cutting tooth around its periphery.

13. In a rotary expansive reaming tool, a vertically elongate body rotatable about a central vertical axis, a cutter carrying mandrel pin extending vertically of the body and having one end mounted in the body for tilting motion, a roller cutter on the mandrel pin and having the end thrust support on the body at the other end of the mandrel pin, and said roller cutter having a spiral cutting tooth around its periphery.

In Witness that I claim the foregoing I have hereunto subscribed my name this16 day of August, 1928.

6D WILLARD N. PACKER. 

